1. Field of Invention
The present invention relates generally to improvements in new and existing chicken house structures and methods of operation which provide uniformity of floor surface, reduce air-borne contaminants, copraphagia, emissions and pathogens, while concurrently improving carbon dioxide removal, meat performance, chicken manure removal, chick brooding and overall chicken welfare, leading to a more economical and humane operation during the growing process. Further, improvements in work environment and waste disposal in the poultry-growing environment are expected. Management efficiency through decreased time interval between growth cycles will be improved.
2. Description of Related Art
The chicken growing industry is based on mass production and low margin in which production casualties or weight reduction that might be considered trivial in other commercial activities can be detrimental to production cost. The magnitude of the industry is evident from the fact that a typical chicken house (approximately 40 to 60 feet by 500 to 600 feet) will house 25,000 to 45,000 birds per flock. At harvest time, a typical commercial chicken house can have a density of 0.8 square feet per chicken or 7.5 lbs/square foot. Each bird will have consumed an average of 1.8 lbs. of feed per pound of chicken and an average of 2.25 gallons of water per pound of chicken by harvest time. Forty percent of the feed and water is consumed during the last week of growth. Broilers are grown to an average of 5.5 lbs. and roasters to an average of 7.25 lbs. The total amount of manure deposited on the floor bedding during each growth cycle is approximately 150,000 lbs. The total amount of excreted water is approximately 50,000 gallons, which makes it impossible to achieve and/or maintain bedding dryness under existing chicken house conditions.
Wet manure and saturated bedding, along with the massive animal heat generated by so many birds, results in perfect environmental conditions for pathogen development and promulgation. Unfortunately, the widespread use of evaporative coolers for reducing the temperature can be counterproductive in that it results in high humidity, which is also conducive to ammonia and pathogen production. As the bacteria feeds on the manure and multiplies, it produces large amounts of ammonia gas, as well as methane gas. The use of ventilation systems for removing ammonia and other gasses is not a satisfactory solution since such use can have undesirable results such as the introduction of cold air into the facility during cold weather with minimal ventilation.
It has been the practice of the poultry industry to require producers to meet certain minimal chicken house conditions. These requirements include providing a compacted dirt floor. Over this dirt floor, three (3) inches of bedding (wood chips, sawdust, straw, chopped cardboard, etc., sometimes referred to as “litter”) are required. The intended purpose of this bedding litter is to provide insulation from the ground and to have the capacity to absorb moisture from the chicken manure.
Another requirement for producers is to provide ventilation capable of changing the total air in the chicken house once per minute during warm weather (tunnel ventilation) and to provide minimum ventilation capable of changing the total air by cross ventilation every 6 to 8 minutes in cold weather, in addition to maintaining a required temperature, water and forage. Such ventilation requirements are not energy efficient.
Conventional chicken house design and ventilation technology in use today consist of tunnel ventilation in warm weather and minimal cross ventilation in cold weather. The humidity retained in the litter, along with the undigested feed and uric acid found in chicken manure, creates a uniquely productive environment for pathogen development and development of ammonia, carbon dioxide, hydrogen sulfide, methane, bacteria and fungus/mold. The present invention is directed to apparatus and methods for alleviating the foregoing problems.
Laminar ventilation of conventional chicken houses in warm weather is provided by a series of exhaust fans located at one end of the elongated chicken house that pulls air through the length of the house (exhaust). On the opposite end of the elongated chicken house, ambient air is pulled through cold water saturated cooling pads (intake) that cool and saturate the air which then travels along the length of the chicken house and is exhausted by the exhaust fans.
The above-described ventilation cooling method suffers from additional shortcomings due to the inability of the moisture-saturated air to absorb additional moisture from the bedding. As the bedding becomes saturated with water and manure, and with the lack of natural light, substantial heat is generated by the bedding thus raising the temperature surrounding the chickens. An environment is thus created for multiplying bacteria and fungus/molds. Moreover, the water-saturated air enhances uric acid decomposition and resultant carbon dioxide and ammonia, as well as methane, emissions. The additional water in the saturated air also increases bacterial production of ammonia in the litter.
Another problem with conventional tunnel ventilation is that it causes the chickens to migrate toward the incoming air seeking fresh oxygenated air, packing themselves in tightly on the air intake end, and causing injuries and bruises. This migration also increases the concentration of manure in this area and also reduces the area for natural water absorption by the bedding, since the chickens defecate in a reduced floor area, which prevents the bedding from evaporating the liquid and precludes bedding drying.
Chicken collection for marketing in today's chicken houses is done manually, or with mechanized catching equipment to a small degree. The manual method consists of several workers (chicken catchers) that chase, catch and hold the birds by their feet. By placing one chicken leg between each finger until they have a hand-full, the chickens are then placed in a cage at a prescribed number. When the cage is full, it is picked up by a forklift and loaded onto a truck for transportation to the processing plant. The mechanized method consists of a self-propelled or motorized vehicle, equipped with a conveyor to carry the chickens out in order to later manually place them in the cage. At the entrance of the conveyor there are two inwardly rotating wheels/brushes; some with rubber fingers, others use plastic materials to pull the chicken onto the conveyor, while simultaneously workers are corralling the chickens toward the conveyor entrance of the machine.
There is a large body of information available with the recommended brooding temperatures during this critical time. All these recommendations are made with the assumption that the starting point is clean dry bedding. The bedding materials used today are absorbent and not able to dry during chicken house down time (typically 13 days) as the manure blocks any ventilation that would be necessary to accomplish this process. As the chicken house is prepared for brooding the temperature is raised above 95° F. Not only is this extremely energy inefficient, but it causes the evaporation of the urine retained by the bedding of the previous flock. This chemical reaction produces large amounts of ammonia gas as well as carbon dioxide. Although the house is at 95° F., the evaporation at floor level where the baby chicks are placed creates a cooling effect. This creates a very poor environment for the baby chicks as their needs are warmth and fresh or properly oxygenated air.
Various designs of manufactured flooring have therefore been developed over the years to attempt to allow the collection of the waste material beneath the floor for removal and further use regularly without disturbing the flock above. In many cases this type of flooring does not allow an operative to properly enter the area where the birds are kept so as to provide the necessary culling or catching of the birds. In some cases this is overcome by providing as the flooring a conveyor belt which will move toward one end at which the birds can be grasped or dead birds removed.
However this type of flooring in many cases has a severe disadvantage that is the birds tend to sit upon transverse wires or strips which support the floor and thus cause indentation in the breast resulting in crooked keel bones and in some cases unsightly breast blisters which are unacceptable in broilers and require the birds to be culled due to health standards and to be used only for soup. Little success has therefore been obtained in providing a flooring which overcomes all of these requirements and while many of the new designs of flooring have been tried, very little commercial success has been attained.